Human and mammalian health is certainly impacted by the spread of microbial entities at home, school, work and in the environment generally. Indeed, viruses and bacteria continue to cause a variety of sicknesses and ailments, prompting high absenteeism in schools and places of employment. In the wake of widespread food poisoning and the like, the public has become even further concerned with sanitization, both of person and property. Consequently, those of skill in the art have focused their research endeavors on the identification and deployment of suitable antimicrobial compositions, and specifically those that provide immediate and residual kill of microbes, with or without the use of water.
A comprehension of the vast benefits achieved via practice of the present invention requires an understanding of the various microbes against which the present compositions are effective. Bacteria found on human skin may be divided into two groups, namely, resident and transient bacteria. Resident bacteria are Gram-positive bacteria that establish as permanent microcolonies on the surface and outermost layers of the skin. Such bacteria play a fundamental role in preventing the colonization of other, more harmful bacteria and fungi. Transient bacteria are bacteria that are not part of the normal resident of the flora of the skin. Rather, transient bacteria are deposited when airborne contaminated material lands on the skin or when contaminated material is brought into physical contact with such bacteria. Transient bacteria are typically divided into two subgroups: Gram-positive and Gram-negative. Gram-positive bacteria include pathogens such as Staphylococcus aureus, Streptococcus pyogenes and Clostridium botulinum. Gram-negative bacteria include pathogens such as Salmonella, Escherichia coli, Klebsiella, Haemophilus, Pseudomonas aeuginosa, Proteus and Shigella dysenteriae. Gram-negative bacteria are generally distinguished from Gram-positive bacteria via the existence of an additional protective cell membrane in the former, which often results in Gram-negative bacteria being less susceptible to conventional, topical antibacterial actives.
There exist several contemporary compositions and methods for reducing and/or eliminating the formation of bacteria and/or viruses. For example, it is well known that the washing of hard surfaces, food (e.g. fruit or vegetables) and skin, especially the hands, with antimicrobial or non-medicated soap, is effective against viruses and bacteria. Actually, removal of the viruses and bacteria is due to the surfactancy of the soap and the mechanical action of the wash procedure, rather than the function of an antimicrobial agent. Thus, it is recommended that people wash frequently to reduce the spread of viruses and bacteria. However, many conventional products and methods of sanitization, including washing, fail to address the dilemma of sanitization “on the go”, that is to say, when a consumer is removed from the benefit of running water. Those skilled in the art have attempted to resolve this dilemma via the incorporation of antimicrobial agents into disinfecting lotions, cleansing wipes and the like. Such articles reduce the need for water during or following the application of the subject composition.
Other conventional antimicrobial cleansing products include deodorant soaps, hard surface cleaners, and surgical disinfectants. These traditional, rinse-off antimicrobial products have been formulated to provide bacteria removal during washing. A few such products, including antimicrobial soaps, have also been shown to provide a residual effectiveness against Gram-positive bacteria, but provide limited residual effectiveness against Gram-negative bacteria. By “residual effectiveness”, it is meant that the subject antimicrobial controls microbial growth on a substrate by either preventing growth of microbes or engaging in continuous kill of microbes for some period of time following the washing and/or rinsing process. To address the dilemma of limited residual efficacy against Gram-negative bacteria, those skilled in the art have sought to incorporate high levels of alcohol and/or harsh surfactants into contemporary antimicrobial products, which have been shown to cause dryness and irritation to skin tissues.
Thus, there remains a substantial need to identify and deploy antimicrobial compositions that may be used by consumers “on the go”; provide immediate and residual kill of microbes with or without washing; and prevent dryness and irritation to skin following application. Despite providing a quasi solution to the dilemma of water availability, those skilled in the art have yet to identify antimicrobial compositions that address the problems associated with dryness and irritation to skin. In fact, attempts to resolve this dilemma have generally resulted in the adoption of aqueous-based antimicrobial formulas incorporating high levels of zwitterionic surfactants that are too weak to provide significant immediate or residual benefits. Others have attempted to address the dilemma of dryness or irritation to skin by incorporating cationic surfactants into antimicrobial compositions, which have been associated with adverse impacts on the environment and human health. Yet others still have attempted to resolve this dilemma via the incorporation of long-chain anionic surfactants into antimicrobial compositions, which are intended to prevent skin tissue penetration. Nevertheless, such surfactants are often associated with poor phase stability in product, incompatibility with commercial antimicrobial agents, and low residual kill performance. Indeed, the identification of a balance between the factors of antimicrobial performance, skin mildness and water availability continues to be a key concern to those of skill in the antimicrobial art.